On/off switches are typically used in small engines, such as gasoline engines incorporated in lawn and garden equipment, to provide a mechanism for turning off the engine. In such a system, the switch should be in an "on" position to start the engine. After the engine is running, the switch should be turned to the "off" position when it is desired to end the operation of the engine. While such a switch may provide for a simple operation of the engine, it has some undesirable qualities, such as relying on the operator to manually position the switch in the off and the on position. If the switch is left in the off position after the engine is turned off at the end of operation, the next time the engine is attempted to be started, the operator must turn the switch to the on position. If the operator inadvertently overlooks the necessity to turn the switch to the on position, an attempt to start the engine may flood the engine, which makes subsequent starting extremely difficult.
Another approach may be to provide a spring loaded switch that is biased to the on position. With such an approach, the operator would not have to remember to turn the switch to the on position for the next start of the engine. However, the operator must manually maintain the switch in the off position until the engine stops rotating. This is undesirable since an operator may hold the switch to the off position for a time less than adequate to completely shut off the engine and then release the switch so that the engine continues to operate, which may result in a dangerous condition.